Sheet material forming

ABSTRACT

A formed sheet metal material ( 100 ) and methods, tools ( 1, 2, 8 ) and apparatus for forming the sheet metal material ( 100 ) in which a pattern of projections and depressions are cold worked in a first portion ( 101 ) and, simultaneously, indicia ( 103 ) is embossed in a second portion ( 102 ) of the sheet material ( 100 ). The cold worked portion ( 101 ) is formed with the projections and depression configured and distributed such that lines drawn on a surface of the formed sheet material ( 100 ) between adjacent rows of projections and depressions are not rectilinear. The indicia ( 103 ) is indicative of the alignment between the tools ( 1, 2, 8 ).

This invention relates generally to sheet material forming and moreparticularly to tools and methods for forming sheet material and toformed sheet material. More specifically, although not exclusively, thisinvention relates to methods and tools for cold forming one or moreprojections and/or depressions on one or more surfaces of a sheetmaterial and to a sheet material so formed.

Several methods of forming sheet material with projections are known,many of which involve passing the sheet material between opposed toolsto form one or more projections on the sheet. Some exemplary sheetforming methods include roll forming, such as cold roll forming,stamping and pressing, such as punching using a machine press orstamping press, blanking, embossing, bending, flanging, knurling orcoining.

The present invention is particularly, although not exclusively,concerned with cold rolling, which is a process of shaping materials bypassing a sheet material between a pair of rollers whilst at atemperature below its recrystallization temperature, usually at roomtemperature. As the material passes between the rollers, it isstrengthened by a process known as strain hardening.

Cold rolling is usually performed on sheet material, fed from a coil ofmaterial. The sheet material is passed between a series of matched pairsof rollers to successively shape the sheet material until it has thedesired configuration, for example, a C, U or box section. The shapedsheet material (hereinafter a section) may then be cut to the desiredlength.

Typically, the sheet material may be metal, for example steel,aluminium, copper, brass, silver, gold, titanium and so on, althoughplastics and other materials may be cold rolled. Steel is most usuallyprocessed. The material may be coated (e.g. galvanized) or uncoated

Proper alignment and indexing of the opposed tools can also be critical,particularly where densely packed projections and/or complex geometriesare involved. As a result of the high forces exerted by the tools in anyof these operations, but particularly in cold forming processes, thetools have a tendency to move out of alignment with one another. Regularand careful inspection of the formed sheet material is often required inorder to ensure proper alignment of the tools.

As will be further appreciated, it is essential to ensure that the rollsare aligned during the start-up process, when the rolls are driven fromrest to or toward their operating rotational speed, to ensure accurateregistration and to prevent damage and so on.

WO2009/063154, the contents of which are incorporated herein byreference, discloses methods and tools for forming a sheet of materialto provide on both of its surfaces rows of projections and rows ofdepressions, wherein the relative positions of the projections anddepressions are such that lines drawn on a surface of the sheet betweenadjacent rows of projections are non-rectilinear. The process describedleads to work hardening of the sheet material. Each projection is formedto have a substantially continuous region of peak plastic strain aboutits apex with material thinning of 25% or less. Proper tool alignment inthis case is crucial to achieve the requisite balance between workhardening and material thinning. Even minor tool misalignment can havean impact, and sometimes a significant impact, upon the formed material,but detection of such minor misalignment can be difficult.

The performance of sheet material that is cold roll formed withprojections is therefore highly dependent upon the quality ofmanufacture. It is therefore desirable to have some means ofestablishing reliably the quality of manufacture and/or the provenanceof such formed sheet material.

It is therefore a non-exclusive object of the invention to provide ameans by which tool alignment and/or provenance can be monitored moresimply and/or effectively. It is a further, more general non-exclusiveobject of the invention to provide an improved sheet forming tool andmethod that at least mitigates the issues with known forming tools andmethods.

According to a first aspect of the invention, there is provided a methodof forming a sheet material, the method comprising the steps of placingor running a sheet material between a pair of tools and moving the toolssuch that the tools, e.g. respective first forming surfaces thereof,form a pattern in a first portion of the sheet material and such thatthe tools, e.g. respective second forming surfaces thereof, form indiciaor a second pattern that is or may be different from the first patternin a second portion of the sheet material, e.g. wherein the indicia orsecond pattern may be indicative of the alignment between the tools.

The pattern may be formed by any forming method, such as cold rollforming, stamping and pressing, blanking, embossing, bending, flanging,knurling or coining or any other suitable forming method, but thepattern is preferably formed by cold working. The indicia or secondpattern may also be formed by any suitable forming method, such as coldroll forming, stamping and pressing, blanking, embossing, bending,flanging, knurling or coining or any other suitable forming method. Theindicia or second pattern is preferably formed by embossing. Morepreferably, the indicia or second pattern is formed by embossing thesheet material such that the indicia or second pattern protrudes out ofthe plane of the sheet material, for example a neutral plane thereof.

According to a second aspect of the invention, there is provided amethod of forming a sheet material, the method comprising the steps ofplacing or running a sheet material between a pair of tools and movingthe tools such that the tools, e.g. respective first forming surfacesthereof, cold work a first portion of the sheet material and such thatthe tools, e.g. respective second forming surfaces thereof, emboss asecond portion of the sheet material. The embossment preferablycomprises indicia and/or protrudes out of the plane of the sheetmaterial, for example a neutral plane thereof.

By forming both indicia (and/or the or a second pattern) and thepattern, for example by including forming surfaces that emboss the sheetmaterial in or on a cold forming tool, the invention enables a simpleand effective means of monitoring tool alignment by relatively unskilledpersons. The inclusion of indicia or second pattern also enables productidentification and/or provenance indicia for tracking and/or brandingpurposes to be provided during the forming operation, rather than in aseparate post-forming step which would increase complexity and cost.Thus, the invention provides a convenient means of ensuring bothtraceability, e.g. retrospective traceability, and trackability, e.g.the ability to track products through the supply chain. Indeed, theindicia can incorporate one or more anti-counterfeiting features.

For the avoidance of doubt and as would be appreciated by the skilledperson, the term ‘cold working’ (also known as ‘cold work hardening’) asused herein refers to the deformation of metal plastically at atemperature below its lowest recrystallisation temperature, where strainhardening occurs as a result of such permanent deformation. In addition,the term ‘embossing’ as used herein refers to the operation of raising adesign or form above and/or below the surface of a component by means ofhigh pressure effected by pressing or squeezing action, and includesdebossing.

It is known that embossing and cold work hardening are distincttechniques. Embossing involves compressing material, in this case sheetmetal, between two tools (e.g. rolls) to reduce its thickness beyond itsultimate tensile strength into the purely plastic range; it is acompression process which uses significant force to squeeze the materialbetween two tools (e.g. rolls), one of which has a projection (orrebate) and the other has a rebate (or projection) whereby the patternon the tool (e.g. roll) is transferred to the material. In contrast,work hardening by cold roll forming involves plastic strain hardening amaterial by locally stretching the material without compression. It isconveniently achieved in our patent applications GB2450765A, EP0891234A(the entire contents of which are incorporated herein) by using pairs ofmatched male forming rolls with the teeth of one of the rolls extending(as the rolls rotate) into gaps between teeth on the other roll.Clearly, the skilled person knows and recognises that the techniques ofembossing and work hardening are distinct and generate differenteffects.

Knurling is also a known cold working process that is distinct from coldworking and embossing. Knurling is a process in which a series of sharpserrations on a hardened steel roller are pressed into the materialbeing knurled. Knurling is used to make a gripping or non-slip surfaceand involves displacing the material sideways using serrations orprojections, rather than pushing projections through the other side ofthe sheet.

For the avoidance of doubt, any of the features described herein applyequally to any aspect of the invention.

The embossing or the forming of indicia or a second pattern may besimultaneous with the cold working or the forming of at least a portionof the pattern and/or the embossing or indicia or second pattern may beat least partially surrounded or encircled or bound or confined by thepattern. The pattern may comprise one or more interruptions and/or theindicia or second pattern may be formed in or at one or more or each ofthe interruptions. The second portion may comprise or be located at orin the one or more interruptions.

The forming of the pattern may comprise forming projections in or on oneor both major surfaces of the sheet material. The forming of aprojection in or on a major surface may comprise or result in adepression, e.g. a corresponding depression, being formed in or on theother major surface. The pattern formed may be such that, e.g.configured and/or distributed such that, lines drawn on a surface of theformed sheet material between adjacent rows of projections anddepressions are not rectilinear.

The method is preferably continuous or at least partially continuous,for example the forming of the sheet material is preferably continuousor at least partially continuous or carried out continuously for atleast a predetermined period of time. The placing or running of thesheet material between the pair of tools and/or the moving the toolsand/or the forming of the pattern and/or indicia may be carried outcontinuously, for example using rollers or roll forming tools.

The tools may be moved such that teeth or projections on one tool urgeportions of the sheet material into gaps between teeth or projections onthe other tool, e.g. thereby to cold work a first portion of the sheetmaterial and form a pattern therein or thereon. Preferably, theseparation of the tools and/or the gaps are configured and/or sizedand/or dimensioned such that the sheet material is cold worked, forexample plastic strain hardened, by locally stretching the materialand/or allowing it to flow freely, e.g. without compression or restraintor pinching.

The embossing or the forming of indicia or a second pattern may compriseforming indicia or a second pattern that is indicative of the alignmentbetween the tools. The tools may be moved such that one or more formingedges of one of the tools forces or compresses the sheet materialagainst the other tool, e.g. thereby embossing the sheet material toform indicia or a second pattern therein or thereon.

Additionally or alternatively, the embossing or the forming of indiciaor a second pattern may comprise forming a small or microscopic indiciaor pattern, e.g. that is visible only under magnification, for exampleusing a magnifying glass or microscope.

The method may further comprise shaping the formed sheet material, forexample into a profile or beam or article having a shaped cross-section,such as a channel section.

A third aspect of the invention provides a forming tool for formingsheet material, e.g. for use in a method according to any precedingclaim, the forming tool comprising a first forming surface, which may beconfigured to form a pattern and/or cold work, in use, a sheet materialor a first portion thereof, and a second forming surface, which may beconfigured to form indicia or a second pattern that may be differentfrom the first pattern and/or emboss the sheet material or a secondportion thereof.

The first forming surface may be configured to form, in use, a patternof projections. The second forming surface may be configured to form, inuse, indicia at an interruption in the pattern of projections.

The first forming surface may comprise a profiled forming surface, whichmay comprise or incorporate or define at least part of a pattern.Additionally or alternatively, the second forming surface may comprise aprofiled forming surface, which may comprise or incorporate or define,at least in part, indicia or a second pattern. In some embodiments, thesecond forming surface of the tool is surrounded or encircled or boundor confined by the first forming surface thereof, e.g. such that theindicia or second pattern formed, in use, is surrounded or encircled orbound or confined by the pattern, for example the first forming surfaceor pattern may comprise one or more interruptions wherein the secondforming surface or indicia or second pattern may be comprised or formedin or at one or more or each of the interruptions. The second formingsurface may be bound in first and second directions, for example whereinthe first and second directions are orthogonal to one another.

Additionally or alternatively, the second forming surface or the indiciaor second pattern may comprise a small or microscopic indicia orpattern, e.g. that is visible only under magnification, for exampleusing a magnifying glass or microscope.

Preferably, the forming tool comprises a substrate or drum or roll or besubstantially cylindrical, for example comprising or with the firstforming surface, e.g. included or incorporated thereon or therein.Additionally or alternatively, the forming tool may comprise an insert,for example comprising or with the second forming surface, e.g. includedor incorporated thereon or therein. The insert may be received and/orreceivable, e.g. removably received and/or receivable, within a recessor depression or hole or aperture of the forming tool. In someembodiments, the insert is secured or securable, e.g. releasably securedor securable, to the tool, for example within the recess or depressionor hole or aperture thereof, such as by a locking means. The insert maybe located or positioned such that the first and second forming surfacesare substantially contiguous and/or adjacent one another and/or suchthat the second forming surface is surrounded or encircled or bound orconfined by the first forming surface or included in or at one or moreinterruptions in the first forming surface, e.g. for forming, in useand/or simultaneously, at least a portion of the pattern and the indiciaor second pattern in or on a sheet material. The second forming surfacemay be surrounded or bound or encircled or confined by the first formingportion or portions in an axial direction or a direction along the axisof rotation of the tool and/or in a circumferential direction or rollingor working direction. The second forming surface, e.g. the insert, maybe surrounded or bound or encircled or confined by portions of the firstforming surface on each side, e.g. each axial side and/or eachcircumferential side. Preferably, the second forming surface issurrounded or bound or encircled or confined in the axial and/or rollingdirections, more preferably both.

A fourth aspect of the invention provides a forming tool for formingsheet material, e.g. for use in a method as described above, the toolcomprising a substrate, an insert and locking means, the substratehaving a first forming surface, which may be profiled, incorporating apattern, the insert having a second forming surface, which may beprofiled, incorporating indicia or a second pattern, wherein thesubstrate comprises a recess within which the insert is removablyreceived and/or receivable and secured and/or securable by the lockingmeans such that the first and second forming surfaces are substantiallyadjacent and/or contiguous one another for forming, in use and/orsimultaneously, at least a portion of the pattern and the indicia orsecond pattern in or on a sheet material.

The indicia or second pattern may be configured to enable, or comprise apredetermined pattern configured to enable detection, e.g. rapid and/orsimplified detection, of misalignment between the tools. In someembodiments, the second forming surfaces is configured to form indiciaor a second pattern that is distorted if the tools are misaligned.

Additionally or alternatively, the indicia or second pattern may bemachine readable and/or indicative of the alignment between the tool andanother, e.g. opposed, tool.

With a complex forming pattern, such as that set out in our earlierpatent application WO2009/063154 (or GB2450765A or EP0891234A), it canbe difficult to determine proper registration visually. However, withcertain indicia or second patterns proper alignment can be determinedimmediately and effectively by even untrained operatives.

The forming tool may comprise a cold forming tool, e.g. for cold forminga sheet material. Additionally or alternatively, the forming tool maycomprise a roll or roller with a circumference, for example wherein thefirst and/or second forming surface(s) is or are provided on thecircumference of the roll or roller. The tool may comprise a cylindricalroll, for example which is rotatable about its axis. Preferably, theforming tool comprises a cold roll former, e.g. for cold roll forming asheet material, such as a sheet metal material, for example an ironbased metal material such as steel or any other metallic material, or asheet material formed of any other material, such as a plasticsmaterial.

The indicia or second pattern may comprise an identification means oridentifier, such as alphanumeric indicia, one or more names or logos orimages or bar codes or quick response (QR) codes. The identificationmeans may comprise a unique identifier relating to the tool or a pair oftools or a forming machine or a manufacturer, e.g. a sheet formingmanufacturer and/or tool manufacturer.

The first forming surface may comprise one or more, for example two ormore, e.g. three, four or more, such as a plurality and/or an array, ofprojections or forming projections or teeth, which may project from afirst base or root surface or diameter. The array of projections maycomprise a plurality of rows and/or columns, e.g. rectilinear and/orhelical rows and/or columns, of projections.

The second forming surface may comprise a stamp or one or moreprojections, e.g. indicia projections or second pattern projections orstamp projections, which may project from a second base or root surfaceor diameter. The second forming surface or the stamp or projection orprojections thereof may be at or located at or in an interruption of theplurality or array of projections or forming projections or teeth of thefirst forming surface. The second forming surface or the stamp orprojection or projections thereof may be recessed with respect to thefirst forming surface and/or with respect to at least one of theprojection or projections or tooth or teeth thereof, e.g. the apex orapexes of the projection or projections or tooth or teeth.

In some embodiments, the second base or root surface or diameter isrecessed with respect to the first base or root surface or diameter.Additionally or alternatively, at least a portion or one, preferablyall, of the stamp or projection or projections of the second formingsurface may be recessed with respect to at least one of the projectionor projections or tooth or teeth of the first forming surface, e.g. theapex or apexes thereof. Additionally or alternatively, at least aportion or one of the stamp or projection or projections of the secondforming surface may comprise a small or microscopic stamp or projectionor projections or indicia or pattern, e.g. that is visible only using amagnifying glass or microscope. In some embodiments, the stamp orprojection or projections of the second forming surface is surrounded orencircled or bound or confined by the projection or projections or toothor teeth of the first forming surface and/or included in or at one ormore interruptions therein or thereof.

The locking means may comprise a lock or locking mechanism. The lockingmeans may, for example, comprise cooperating features or lockingfeatures in or on or connected to or associated with each of the insertand the recess or forming tool or substrate or drum or roll. Thecooperating features may comprise a locking recess and a lockingprojection or member or pin or ball, e.g. for engaging the lockingrecess. The cooperating features may be operable between locked andunlocked conditions, for example wherein the insert is secured withinthe recess by the locking means when the cooperating features are in thelocked condition and/or wherein the insert is removable from the recesswhen the cooperating features are in the unlocked condition.

The locking projection or member or pin or ball may be movable, e.g.between a deployed and undeployed or retracted position or conditionand/or between a locked and unlocked position or condition. The lockingrecess may comprise an engaging or bearing surface, for example atapered or slanted or sloped engaging or bearing surface, which may beat an angle or be oriented or orientated or extend at an angle, e.g. anon-orthogonal and/or non-parallel and/or acute or oblique angle, withrespect to the direction of movement of the locking projection or memberor pin or ball. The locking projection or member or pin or ball may beresiliently biased toward the deployed or locked position or condition.In other embodiments, the locking projection or member or pin or ballmay be resiliently biased toward the undeployed or retracted or unlockedposition or condition, for example by a resilient means or a biasingmeans or a resilient biasing means, such as a spring, e.g. a compressionspring.

In one preferred embodiment, the insert comprises the locking recess andthe locking projection or member or pin or ball is mounted, e.g. movablymounted, to or otherwise associated with, e.g. movably associated with,the recess or forming tool or substrate or drum or roll. The lockingprojection or member or pin or ball and/or the resilient means orbiasing means or resilient biasing means may be received within a cavityor recess or depression or aperture or hole, which may be in or locatedor positioned in or associated with the tool recess or forming tool orsubstrate or drum or roll. Additionally or alternatively, the lockingprojection or member or pin or ball and/or the resilient means orbiasing means or resilient biasing means may abut and/or be retained orsecured or held in place, e.g. within the cavity or recess or depressionor aperture or hole, by a fastener, such as a bolt.

The tool may have a first end and a second end, for example with drivingmeans being located at or toward one of the first and second end and/orthe other end being free of driving means. The tool may further comprisean aperture for receiving a shaft.

Other aspects of the invention provide an insert for use in a tool asdescribed above and/or a tool or tool substrate or drum or roll for usein a forming tool as described above and/or a kit of parts for assemblyinto a tool or pair of tools as described above. The insert and/or toolor tool substrate or drum or roll and/or kit of parts may include anyone or more components or features described above that would beadvantageous and/or desirable, as would be clear to the skilled person.

A further aspect of the invention provides a pair of forming tools forforming sheet material therebetween, e.g. for use in a method asdescribed above, wherein a first of the forming tools may comprise aforming tool as described above, e.g. with respect to the third orfourth aspects of the invention.

A yet further aspect of the invention provides a pair of forming toolsfor forming sheet material, e.g. for use in a method as described above,each forming tool comprising a first forming surface and a secondforming surface, wherein the first forming surfaces of the forming toolsmay be configured to cooperate, in use, to cold work a sheet materialtherebetween and the second forming surfaces of the forming tools may beconfigured to cooperate to emboss the sheet material therebetween, forexample such that the embossed feature or features protrude out of theplane of the sheet material, for example a neutral plane thereof.

For the avoidance of doubt, each of the opposed forming tools describedin relation to any relevant aspect of the invention may comprise any oneor more features described in respect of the other or another formingtool or tools.

A second of the forming tools may comprise a first forming surface forcooperating, in use, with the first forming surface of the first tool toform a pattern. Additionally or alternatively, the or a second of theforming tools may comprise a featureless surface, wherein the secondforming surface of the first forming tool comprises a profiled formingsurface that cooperates, in use, with the featureless surface to formindicia or a second pattern on a sheet material formed therebetween. Inanother embodiment, the or a second of the forming tools comprises asecond profiled forming surface, wherein the second forming surface ofthe first forming tool cooperates, in use, with the second surface ofthe second forming tool to form indicia or a second pattern on a sheetmaterial formed therebetween. The second profiled forming surfaces maycooperate to form indicia or a second pattern that is distorted if thetools are misaligned. Additionally or alternatively, the second formingsurfaces may cooperate to form indicia or a second pattern at least aportion of which may comprise a small or microscopic indicia or pattern,e.g. that is visible only using a magnifying or looking glass ormicroscope. In some embodiments, the second forming surface of thesecond forming tool is surrounded or encircled or bound or confined bythe first forming surface thereof or included in or at interruptionsthereof or therein, e.g. such that the indicia or second pattern formed,in use, is surrounded or encircled or bound or confined by the pattern.

Another aspect of the invention provides a pair of forming tools forforming sheet material therebetween, e.g. one or each of which maycomprise a forming tool as described above, each of the forming toolscomprising a respective first forming surface and a respective secondforming surface, wherein the first forming surfaces cooperate, in use,to form a pattern while the second forming surfaces cooperate to form,e.g. simultaneously, indicia or a second pattern, which may be distortedif the tools are misaligned.

The second forming surfaces may cooperate, in use, to form indicia or asecond pattern that is visibly distorted if the tools are misaligned,for example wherein the distortion is readily detectable by the humaneye. In some embodiments, at least a portion of the indicia or secondpattern may be small or microscopic, e.g. visible only using amagnifying glass or microscope, and/or machine readable, for example byscanning using a scanning means or scanner. The indicia or secondpattern may be configured such that tool misalignment or identificationcan be detected or the extent of tool misalignment can be determined byreading or scanning the indicia or second pattern, for example using ascanning means or scanner, and/or by processing the read or scannedindicia or second pattern using a processing means or algorithm orcomputer. One non-limiting example of such indicia or second patterncould be a bar code or quick response (QR) code. In some embodiments,the second forming surface of one or each tool is surrounded orencircled or bound or confined by the first forming surface thereof,e.g. such that the indicia or second pattern formed, in use, issurrounded or encircled or bound or confined by the pattern and/orincluded in or at one or more interruptions therein or thereof.

The first forming surfaces may cooperate, in use, to form a patterncomprising one or more projections and/or depressions, which may bearranged in an array and/or may be formed, in use, on one, preferablyboth, major surfaces of a sheet material, for example thereby definingan effective thickness or amplitude, e.g. defined between the peaks ofthe projections on each side of the sheet material. The pattern maycomprise a plurality of rows and/or columns, e.g. rectilinear and/orhelical rows and/or columns, of projections and/or depressions. Thepattern or array may be configured and/or distributed such that linesdrawn on a surface of the formed sheet material between adjacent rows ofprojections and depressions are not rectilinear. The second formingsurfaces may cooperate to form the indicia at an interruption in thepattern of projections.

Preferably, the second forming surfaces comprise cooperating formingedges, which may be separated by a predetermined distance, in use, whena sheet material is formed between the tools and/or when the tools arein proper alignment. In some embodiments, one of the second formingsurfaces comprises a male forming surface or projection and the other ofthe second forming surfaces comprises a corresponding female formingsurface or projection or depression, which depression may be formed inthe or a base or root surface or diameter and/or may be defined ordelineated by one or more projections that may be offset with respect tothe male forming surface or projection. Cooperation of the male formingsurface or projection and the female forming surface or depression maybe such that a predetermined degree of misalignment results in a visualindication of distortion.

The tools may comprise first and second tools, which may be operable topattern a sheet material in use. Each tool preferably has a first endand a second end with driving means located at or toward one of thefirst and second ends, the other end preferably being free of drivingmeans, e.g. which driving means in use, may intermesh, for example toallow the tools to be driven.

Yet another aspect of the invention provides an apparatus for formingsheet material, the apparatus comprising a pair of opposed tools, e.g.as described above. The tools are preferably movable relative to oneanother, which tools may each comprise or be provided with formingsurfaces, e.g. forming projections or teeth that may be configured orable to intermesh with forming projections or teeth on the other tool.In embodiments where the apparatus comprises a pair of opposed tools asdescribed above, the first forming surfaces may comprise projections orteeth and the geometry and/or position of the projections or teethand/or the spacing of the tools is such that the projections or teeth onone tool register and/or extend, in use, into gaps between theprojections or teeth on the other tool.

Another aspect of the invention provides an apparatus for forming sheetmaterial, e.g. a cold rolling apparatus, the apparatus comprising firstand second tools, each being provided with forming projections which areable to intermesh with forming projections on the other, the tools beingoperable to pattern a sheet material in use, each tool having a firstend and a second end and each having driving means located at or towardone of the first and second end the other end being free of drivingmeans, the driving means in use, intermeshing to allow the tools to bedriven.

Each of the first and second tool may comprise an aperture for receivinga shaft.

Yet another aspect of the invention provides a forming tool for formingsheet material, for example for use in an apparatus as described above,e.g. a tool for cold rolling, the tool being provided with formingprojections which are able to intermesh with forming projections onanother tool to pattern a sheet material in use, the tool having a firstend and a second end, driving means being located at or toward one ofthe first and second end the other end being free of driving means.

The tool may comprise an aperture for receiving a shaft.

It has been surprisingly found that rather than introducing a potentialdestabilising force when driving the rolls, having driving means at oneend of the rolls rather than both does not have a deleterious effect onregistration accuracy and continuing alignment of the patterned sheetmaterial and also reduces the cost of the roll and associated drivemeans (motors, gear chains etc.) and the setup up time.

The driving means preferably comprise gears, for example spur gears.

In embodiments where the tool comprises a cylindrical shape, the peaksof the projections or teeth may define a nominal tooth-peak diameterd_(TP) (e.g. that being the nominal diameter of the roll atcircumference defined by the peaks of the teeth) in the circumferentialdirection.

The spur gears preferably have an outside diameter d_(O).

Preferably, the ratios of the tooth-peak diameter, d_(TP) to the outsidediameter d_(O) is in the range of 0.5 to 1.5, say, 0.6 to 1.4, 0.7 to1.3, 0.8 to 1.2, 0.9 to 1.1, for example from 0.91, 0.92, 0.93, 0.94,0.95, 0.96, 0.97, 0.98, 0.99 to 1.1, 1.09, 1.08, 1.07, 1.06, 1.05, 1.04,1.03, 1.02, 1.01 and most preferably 1.0.

Preferably, the spur gears have a pressure angle of between 16 and 30°,say between 18 and 27°, for example between 19 and 26°. Pressure anglesof 20° and/or 25° may be used, or angles therebetween.

The pitch circle diameter (D_(PCD)) of the spur gear is preferablycalculated according to the following formula

D _(PCD) =d _(TP)−(g+k)  (1)

Where g is the gauge of the material to be processed

-   -   k is a constant, selected to lie within the range from 0.01 to        0.5, say from 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09 to        0.45, 0.40, 0.35, 0.30, 0.25, 0.2, 0.15, for example 0.05 to        0.15, say 0.06, 0.07, 0.08, 0.09 to 0.14, 0.13, 0.12, 0.11, most        preferably k is 0.1

The number of teeth (N) required for a particular spur gear can then becalculated from the module m, as follows:

D _(PCD)=(N+2)×m  (2)

The Diametrical Pitch (P), can then be calculated, viz:

P=N/D _(PCD)  (3)

The tooth thickness, addendum (A) and dedendum (D) of the teeth of thespur gear can then be calculated depending on the pressure angle.

It has been surprisingly found that matching the pitch circle diameterD_(PCD) to d_(TP), within the above-identified relationship, has theeffect of reducing damage to the spur gear during use.

At least one of the tools may comprise a body portion which carries onits periphery the forming projections. The forming projections may beintegral with or secured to the body portion. At one end, the bodyportion may comprise a recess, outboard of the aperture for the shaft.The recess may be bounded by a peripheral wall. Located within therecess may be a rebate defining the datum position. A datum key may belocatable at least partially within the rebate.

The driving means, e.g. gear or spur gear, may comprise a rebate toreceive the or a datum key to define a spur gear datum position.Preferably, the driving means, e.g. gear or spur gear, comprises andextension, shaped to engage the or a recess on the tool.

The driving means, e.g. gear or spur gear, may comprise an interruptedextension, the interruption(s) being shaped to receive an end of the ora datum key.

A further aspect of the invention provides a method of manufacturingrolling apparatus, the method comprising:

-   -   a) providing a blank tool having a cylindrical periphery and a        central aperture for receiving a shaft;    -   b) determining a tool datum position;    -   c) forming a cold rolling pattern on the cylindrical periphery;    -   d) securing a driving means to one end of the tool such that a        driving means datum position is aligned with the tool datum        position.

The method may further comprise using the tool datum position to definea cold rolling pattern datum position, which is preferably utilised toprovide an alignment position for the cold rolling pattern.

There is a further provided a tool for cold rolling, the tool having acylindrical profile, a central aperture for receiving a shaft and at oneend a rebate, located or locatable within the rebate is a key toestablish a datum position, the key also being received or receivable indriving means secured or securable to the end of the tool.

It has been found that by referencing to the forming pattern and thedriving means to a datum position a more accurate pattern registrationis afforded the process and less damage may be suffered by the rollsand/or drive means in use.

Preferably the aperture defines a circular portion and an elongateradial portion, the shaft received or receivable therein beingcomplementarily shaped thereto so as to be able to cause rotation of thetool in use.

Yet another aspect of the invention provides a sheet material, forexample a formed sheet material, e.g. formed by a tool or a pair oftools as described above. The sheet material preferably comprises apattern formed on or in a first portion or region thereof and indicia ora second pattern formed on or in a second portion or region thereof.Additionally or alternatively, the sheet material may comprise a firstportion or region that is cold worked and a second portion or regionthat is embossed. The indicia or second pattern or second portion orregion may be embossed such that the indicia or second pattern protrudesout of the plane of the sheet material, for example a neutral planethereof.

The indicia or second pattern preferably provides a visual and/ormachine readable indication of the alignment and/or identification oftools, e.g. opposed tools, used to form the sheet material. For example,the indicia or second pattern may comprise a predetermined patternconfigured specifically to enable rapid and/or simplified detection ofmisalignment between the tools. In some embodiments, the indicia orsecond pattern is distorted if the tools are misaligned and/or thedegree of distortion of the indicia or second pattern or embossingcorresponds to the degree of misalignment of the tools. Additionally oralternatively, at least a portion of the indicia or pattern may be smallor microscopic, e.g. visible only using a magnifying or looking glass ormicroscope. In one or some embodiments, the indicia or second pattern ison a flat, e.g. unformed, surface of the sheet material and/or is atleast partially (e.g. entirely) surrounded or encircled or bound orconfined by the pattern. For example, the pattern may comprise one ormore interruptions and/or the indicia or second pattern may be formed inor at one or more or each of the interruptions.

The pattern preferably comprises one or more projections, which may bearranged in an array and/or may be on one, preferably both, of its majorsurfaces, for example thereby defining an effective thickness oramplitude, e.g. defined between the peaks of the projections on eachside of the sheet material. The pattern may comprise projections orpeaks and/or depressions in or on one or both major surfaces of thesheet material. One or more or each of the depressions on one of themajor surfaces may have a corresponding projection or peak on the otherof the major surfaces or vice versa. In embodiments, the patterncomprises projections in or on one or both major surfaces of the sheetmaterial, for example each projection having a corresponding depressionon the other or opposite major surface of the sheet material. The sheetmaterial preferably comprises a central or neutral plane, for examplecorresponding to a plane or a central plan of the sheet material priorto forming. Projections formed on a first major surface of the formedsheet material may be formed on a first side of the central or neutralplane and/or projections formed on a second major surface, e.g. oppositethe first major surface, of the formed sheet material may be formed on asecond side of the central or neutral plan, e.g. opposite the firstside. Similarly, depressions formed on the first major surface, whichmay correspond to projections formed on the second major surface, mayalso be formed on or pass through to the first side of the central orneutral plane and/or depressions formed on the second major surface,which may correspond to projections formed on the first major surface,may also be formed on or pass through to the first side of the centralor neutral plane.

The pattern may comprise a plurality of rows and/or columns, e.g.rectilinear and/or helical rows and/or columns, of projections. Theprojections and depressions, e.g. the pattern or array, may beconfigured and/or distributed such that lines drawn on a surface of thematerial between adjacent rows of projections and depressions are notrectilinear.

Each projection is preferably plastic strain hardened, for examplehaving been formed by deforming the sheet material locally, e.g. toleave a corresponding depression at the opposite face of the material.

The sheet material may comprise steel, for example, mild steel and maybe galvanised. Alternatively, the sheet material may comprise any othermaterial, preferably but not necessarily one that is capable of strainhardening and/or plastic deformation.

The sheet material may comprise a profile or shaped or bentcross-section such as a channel section or the like for use as a, or aspart of a, partition or channel stud. The pattern and/or indicia orsecond pattern may be formed over all or part of the shaped section.Preferably, the indicia or second pattern is formed in or on a flat,e.g. unformed, surface of the sheet material, e.g. that is devoid of anybends or folds.

Another aspect of the invention provides a profile or beam or articlehaving a shaped cross-section, which profile or beam or article may havea shaped cross-section comprising a sheet material as described above.The profile or beam or article may comprise a first portion having peaksand depressions, which may be formed by cold working the sheet material.The profile or beam or article may comprise a second portion, which maybe at an interruption of the peaks and depressions. The second portionmay comprise one or more raised or rebated regions formed by embossing,e.g. embossing the sheet material such that the regions protrude or arerebated out of the plane of the sheet material, for example a neutralplane thereof. The second portion preferably provides indicia.

The pattern may be continuous, for example the projections and/ordepressions may together provide a continuous pattern. The pattern maycomprise a continuous region of peaks and depressions, which may be solocated that the surface of the sheet material has no rectilinear lines.The pattern and indicia preferably together provide a repeat pattern,for example which may be formed by roll forming tools.

Yet another aspect of the invention provides a method for determiningthe quality of a formed sheet material, for example a method for or ofquality control, the method comprising determining using the indiciawhether the tools are aligned.

A further aspect of the invention provides a quality control methodcomprising forming using a pair of tools a pattern on or in a firstportion of a sheet material, forming using the tools, e.g. the same pairof tools, indicia on or in a second portion of the sheet material andchecking or observing or assessing or determining, e.g. using theindicia, whether the tools are aligned.

Yet further aspects of the invention provide a formed sheet material, atool, a pair of tools and an apparatus for use, e.g. specificallyadapted for use, in the aforementioned method.

Embodiments of the invention will now be described by way of exampleonly with reference to the accompanying drawings in which:

FIG. 1 is an end view of a forming tool according to one embodiment ofthe invention;

FIG. 2 is a perspective view of a segment of the forming drum of theforming tool of FIG. 1;

FIG. 3 is a section view along line A-A of FIG. 1;

FIG. 4 is a plan view of the radial hole in the tool of FIG. 1;

FIG. 5 is a perspective view of the marking insert for incorporationinto the forming tool of FIGS. 1 to 3;

FIG. 6 is a side view of the marking insert of FIG. 4;

FIG. 7 is a section view along line B-B of FIG. 5;

FIG. 8 is a side view of a forming tool for cooperation with the tool ofFIG. 1;

FIG. 9 is an exploded view of the forming tool of FIG. 1 illustrating anexemplary driving assembly in more detail;

FIG. 10 is a perspective view of a first end of the tool of FIGS. 1 and9;

FIG. 11 is a perspective view of a second end of the tool of FIGS. 1 and9;

FIG. 12 is a perspective view of an aligned pair of tools according toan embodiment of the invention; and

FIG. 13 is a top view of a sheet material according to an embodiment ofthe invention.

Referring now to FIGS. 1 to 4, there is shown a forming tool 1, which isa cylindrical roll former 1 in this embodiment, for cold roll forming asheet material. The tool 1 includes a central forming drum 2, first andsecond end parts 3, 4, an insert 5, a pair of locating rings 6 andlocking mechanism 7 for releasably securing the insert 5 within theforming drum 2.

The forming drum 2 is in the form of a hollow cylinder or roll thatprovides a substrate on which a first profiled forming surface 21 isincorporated on its outer circumferential surface. In this embodiment,the first profiled forming surface 21 incorporates a pattern ofprojections 21 a arranged in an array having a plurality of rows andcolumns. The forming drum 2 includes at least one, and preferably a pairof, coaxial radial holes 22, 23 located preferably centrally along itslongitudinal axis, the hole 22, 23 or each of which includes acounterbore 22 a, 23 a extending inwardly from the outer circumferenceof the forming drum 2. The counterbores 22 a, 23 a are substantiallyrectangular in plan with rounded corners, as shown more clearly in FIG.4. The counterbore 23 a of one of the radial holes 23 includes onerounded corner 20 a having a larger diameter than the other roundedcorners of the counterbore 23 a. The holes 22, 23 and correspondingcounterbores 22 a, 23 a need not be of the same dimensions. The holes22, 23 and corresponding counterbores 22 a, 23 a need not be coaxial.

The forming drum 2 also includes eight longitudinal through holes 24extending parallel to the axis of the forming drum 2 and spaced equallyfrom and about the longitudinal axis. Each end of each longitudinal hole24 is tapped with a female thread for cooperation with a respectivethreaded bolt 30, 40. Each axial end of the forming drum 2 includes arecess 25, 26 for receiving a portion of a respective one of the firstand second end parts 3, 4.

The first end part 3 is in the form of a substantially cylindrical discwith a central hole 31, a radial flange 32 on a first side thereof andeight holes 34 extending through the thickness of a central portion ofthe disc with positions corresponding to those of the through holes 24in the forming drum 2. Each of the through holes 34 includes acounterbore 34 a on the first side of the first end part 3 foraccommodating the head of a respective bolt 30. The second side of thefirst end part 3 is received within a first of the end recesses 25 ofthe forming drum 2 and secured thereto by eight bolts 30 extendingthrough the through holes 34 of the first end part 3 and engaging thefemale threads in the through holes 24 of the forming drum 2 with one ofthe locating rings 6 captivated between the end of the forming drum 2and the radial flange 32.

The second end part 4 is in the form of a hollow cylindrical spur gearmember 4 with an axial hole 41 therethrough, a plurality of gear teeth42 extending outwardly therefrom, a radial undercut providing a shoulder43 on a first side thereof and eight through holes 44 with positionscorresponding to those of the through holes 24 in the forming drum 2.Each of the through holes 44 includes a counterbore 44 a on a secondside of the second end part 4, opposite the first side, foraccommodating the head of a respective bolt 40. The undercut, first side43 of the second end part 4 is received within a second of the endrecesses 26 of the forming drum 2 and secured thereto by eight bolts 40extending through the through holes 44 of the second end part 4 andengaging the female threads in the through holes 24 of the forming drum2 with the other locating ring 6 captivated between the gear teeth 42 ofthe second end part 4 and the end of the forming drum 2.

As shown more clearly in FIGS. 5 to 7, the insert 5 is in the form of asubstantially rectangular block with rounded vertical corner edges 50,50 a to provide an upper forming face 51 that is substantiallyrectangular in plan with rounded edges. One of the corner edges 50 a hasa slightly larger radius than the others for cooperation with therounded corner 20 a of the counterbore 23 a within which the insert 5 isto be received to ensure proper orientation.

The base surface of the forming face 51 of the insert 5 is curved toprovide a constant depth recess in the circumference of the forming drum2 when the insert 5 is received therein. The upper forming face 51includes forming edges 52 that delineate a brand logo in thisembodiment. The forming edges 52 delineate the outline of the letters ofthe logo with the letters themselves appearing as depressions 52 awithin the delineated outline or between the forming edges 52.

The insert 5 also includes on a first side thereof a locking recess 53with a flat ledge 54 that is substantially parallel to the forming face51 and a tapered surface 55 opposite the flat ledge 54 to provide a widemouthed locking recess 53 that tapers to a narrow base 56 skewed towardthe flat ledge 54. The insert 5 also includes a cutout 57 in a secondside thereof, opposite the first side, and in the bottom of the insert5. The cutout 57 is inclined, to provide a lead-in edge, in the samedirection as the tapered surface 55 of the locking recess 53.

The locking mechanism 7 includes a locking pin 70 and a compressionspring 71, both of which are captivated within one of the through holes24 in the forming drum 2 between one of the bolts 40 and the lockingrecess 53 of the insert 5. As shown more clearly in FIG. 3, the insert 5is received within the counterbore 23 a of one of the radial holes 23 ofthe forming drum 2 with the locking recess 53 facing the second end part4. The locking pin 70 has a first, rounded end that is received withinthe locking recess 53 and engages the tapered surface 55. The lockingpin 70 is biased by the spring, which is compressed between the end ofthe bolt 40 and a second, flat end of the locking pin 70. The provisionof a biased locking pin 70 that engages a tapered surface 55 providesretaining forces along both the axis of the insert 5 and the axis of thelocking pin 70.

With the insert 5 received and retained with the counterbore 23 a of theradial hole 23 of the forming drum 2, the forming face 51 issubstantially contiguous with and adjacent the first profiled formingsurface 21, albeit recessed slightly with respect thereto. Thus, as thetool 1 forms a sheet material, both the indicia and a portion of thepattern are formed simultaneously.

Turning now to FIG. 8, there is shown the forming drum 8 of a secondtool, which is also in the form of a cylindrical roll former and issubstantially similar to the forming drum 2 of the first tool 1, whereinlike features are depicted with like reference numbers with the prefix 2replaced with the number 8. The second tool assembly includes theforming drum 8, first and second end parts, 3, 4, locating rings 6 and alocking mechanism 7 assembled in a similar manner to that describedabove in relation to the first tool 1. The radial hole 83 is adapted toreceive an insert (not shown), which may be a blank having a featurelessforming surface for cooperating with the forming edges 52 of the insert5 of the first tool 1 to mark a sheet material with indicia.

Alternatively and in accordance with one aspect of the presentinvention, the insert (not shown) may include forming edges thatcooperate with the forming edges 52 of the insert 5 to provide theindicia. For example, the forming edges of the further insert maycomprise forming edges that are received by and/or register with thedepressions 52 a within the delineated outline or between the formingedges 52. It will be appreciated by those skilled in the art that withsuch an arrangement, any misalignment between the tools 1, 8 would bereadily visible by a distortion of the logo.

In further preferred alternative embodiments, the forming edges 52 maydelineate indicia which is or are configured to be machine readable, forexample in the form of one or more bar codes and/or quick response (QR)codes. In such embodiments, even minor distortion resulting from amisalignment between the tools 1, 8 may be detected using computerisedscanning and processing. In fact, it is envisaged that the indicia maybe selected such that the nature of the misalignment may be discernablefrom the extent and nature of the distortion. The use of QR codes orsimilar types of indicia could form the basis of such an arrangement.

The tools 1, 8 are rotatably mounted within an apparatus (not shown) apredetermined distance apart and interconnected by their respectivedriving means (not shown), which drives the gear teeth 42 of the secondend part 4 to ensure that they contra-rotate at the same speed. Rotationof the tools 1, 8 causes the array of projections 21 a on the first tool1 to register and extend into gaps between the projections (not shown)on the other tool 8.

In use, the tools 1, 8 cooperate to form a pattern of projections anddepressions in a sheet material fed between them, while the locatingrings 6 retain the sheet material between them. As the tools 1, 8rotate, the projections 21 a on one tool 1 urge portions of the sheetmaterial into gaps between the projections (not shown) on the other tool8, thereby defining an effective thickness or amplitude defined betweenthe peaks of the projections on each side of the sheet material. In thisembodiment, the material is sheet steel and the forming of the patternof projections and depressions results in plastic strain hardening ofthe sheet material, having been formed by deforming the sheet materiallocally, as explained in more detail in WO2009/063154 (and/or one ofGB2450765A and EP0891234A).

In addition, as the tools 1, 8 form the pattern of projections anddepressions in the sheet material, the forming edges 52 of the insert 5bear against the blank (not shown) in the other tool 8 to emboss theindicia on the sheet material. Alternatively, where the insert (notshown) in the other tool includes further forming edges, these maycooperate with the forming edges 52 of the insert 5 to emboss orotherwise form the indicia.

Turning now to FIGS. 9 to 12, each of the recesses 25, 26 (only one ofwhich is shown) of the forming drum 2 is circular in plan and bound byan annular wall 26A. Equi-spaced about the recess 26 and inboard of theannular wall 26A, are a series of rebates 27A, 27B, 27C for receiving anend of respective datum keys 28A, 28B, 28C. The shoulder 43 of the spurgear member 4 includes three interruptions 45 (only one of which isshown) which are complementarily shaped to receive the other end of thedatum keys 28A, 28B, 28C.

When engaged, the interrupted shoulder 43 extends through the locatingring 6 and lies against the circular recess 26 and is bounded by theannular wall 26A with the datum keys 28A, 28B, 28C partly received inthe interruptions 45.

The central hole 31 of the first end part 3 includes a keyway 31A andthe central hole 41 of the spur gear member 4 includes a correspondingkeyway 41A aligned with the keyway 31A of the first end part 3 when thetool 1 is in an assembled condition, thereby to receive a keyed drivingshaft (not shown).

In order to fabricate a set of tools 1, 8 according to the invention,the following process is followed.

Firstly, it is determined what sort of patterned and correspondingpatterning process is required. The type of tooth form, the height ofthe tooth, inter-tooth pitch (in rows and columns) are all importantcharacteristics to be considered when seeking to manufacture aparticular patterned sheet material. Thus, once the tooth form isdetermined, a blank roll 2 is provided. One of the recesses (e.g. 26) isused to determine a roll datum position DP. The tooth form is thenprovided on the outer periphery 21 of the forming drum 2, for example,by one or more of cutting, milling, grinding, etching and so on, butusing the datum position DP to determine the starting position for theforming operation.

As shown is FIG. 12, the spur gear 4 is also aligned to the datumposition DP to provide a gear datum alignment position DA_(G) on boththe gear (e.g. the spur gear 4 of the first tool 1) and in the pinionDA_(p) (e.g. the spur gear 4 of the second tool 8).

In this way it is clear that the pattern formed on the rolls 1, 8 andthe position of the spur gears 4 are aligned to a single defined pointon each roll 1, 8.

Moreover, once the desired patterning process has been established, thespur gear form is calculated according to equations (1) to (3):—

-   -   d_(TP)=162 mm

In one exemplary embodiment, the sheet material to be rolled is 0.6 mmthick (i.e. g=0.6 mm) steel.

In this instance, the spur gear 4 has the following characteristics,(setting k=0.1 and d_(TP):d₀=1);

-   -   DPCD=162−(0.6+0.1)        -   =161.3 mm    -   N=80    -   P=0.5    -   Addendum (A)=2    -   Dedendum (D)=2.3    -   Tooth thickness (T)=3.14    -   Pressure angle=20°

The shaft (not shown) extending through the first tool 1 is driven by amotor at a first ‘jog’ speed which causes rotation of that tool 1 and,through the action of the intermeshing spur gears 4, causedcontra-rotation of the other roll 8.

With the rolls 1, 8 being driven at a first speed, the sheet material isfed through the nip and onto the subsequent forming rollers. Once thematerial is fed through all of the stations, the rolls 1, 8 are drivenat their faster running speed and the process of manufacturingcommences.

It is of note that once the material to be patterned passes into thenip, the rolls 1, 8 are separated slightly, thereby causing separationof the spur gears 4. This separation ensures that the teeth of the gearsdo not contact at the previous line of action and thus are not drivinglyengaged. At this point, the rolls 1, 8 are driven by the action of thedrive means direct to the shafts.

Referring now to FIG. 13, there is shown a sheet material 100 comprisinga cold worked region 101 in which a pattern of projections is formed onboth major surfaces, each projection having a corresponding depressionon the opposite major surface. The pattern is formed such that linesdrawn on a surface of the formed sheet material between adjacent rows ofprojections and depressions are not rectilinear. The sheet material 100also includes a series of interruptions 102 in the cold worked patternon which is formed indicia 103.

It will be appreciated by those skilled in the art that severalvariations to the aforementioned embodiments are envisaged withoutdeparting from the scope of the invention. For example, other sheetmaterials may be formed by the present invention, which may, but neednot, comprise steel or metal or even plastics material. The formingedges 52 may be configured to delineate or define any indicia, such asalphanumeric indicia, one or more images or a unique identifier relatingto the tool or a pair of tools or a forming machine or a manufacturer,e.g. a sheet forming manufacturer and/or tool manufacturer. Moreover,the locking mechanism 7 need not include a spring-biased locking pin 70,e.g. it may comprise any suitable locking arrangement such as a ball anddetent arrangement or even a bayonet-type locking mechanism or any othertype of locking mechanism or means. Several other variations will beappreciated from the disclosure herein or recognised readily by theskilled person.

It will also be appreciated by those skilled in the art that any numberof combinations of the aforementioned features and/or those shown in theappended drawings provide clear advantages over the prior art and aretherefore within the scope of the invention described herein.

1-43. (canceled)
 44. A method of forming a sheet metal material, themethod comprising the steps of locating a sheet material between a pairof tools and moving the tools such that the tools form simultaneously apattern of projections on both major surfaces of the sheet material bycold working in a first portion of the sheet metal material and indiciaby embossing in a second portion of the sheet metal material at aninterruption in the pattern of projections, wherein the form of theindicia is indicative of the alignment between the tools.
 45. A methodaccording to claim 44, wherein the forming of the pattern comprisesforming projections distributed such that lines drawn on a surface ofthe formed sheet material between adjacent rows of projections anddepressions are not rectilinear.
 46. A method according to claim 44,comprising moving the tools such that one or more forming portions ofone of the tools forces or compresses the sheet material against theother tool, thereby embossing the sheet material to form the indiciatherein or thereon.
 47. A method according to claim 44, wherein thesecond portion is surrounded or bound by the first portion.
 48. A coldforming tool for cold forming a sheet material according to the methodof claim 44, the forming tool comprising a first forming surfaceconfigured to form, in use, a pattern of projections in a first portionof a sheet metal material and a second forming surface configured toform indicia in a second portion of the sheet metal material that is atan interruption in the pattern of projections, where the second formingsurface is recessed with respect to at least a portion of the firstforming surface.
 49. A tool according to claim 48, wherein the toolcomprises a substrate including the first forming surface and an insertremovably received within a recess of the substrate, which insertincludes the second forming surface and wherein the insert is secured orsecurable within the recess by a lock.
 50. A tool according to claim 48,wherein the second forming surface is configured to form, in use, in asheet metal material indicia that provides a visual indication of thealignment between the tool and another tool with which the toolcooperates.
 51. A tool according to claim 48, wherein the second formingsurface is configured to form, in use, in a sheet metal material indiciathat is distorted if the tool is misaligned with another tool with whichthe tool cooperates.
 52. A tool according to claim 48, wherein thepattern comprises an array of projections and the indicia comprises anidentifier.
 53. A pair of cold forming tools for cold forming sheetmetal material therebetween, the pair of tools comprising a firstforming tool according to claim 44 and a second forming tool, the secondforming tool comprising a first forming surface for cooperating with thefirst forming surface of the first tool to form a pattern in or on asheet metal material formed therebetween and a featureless surface forcooperating with the second forming surface of the first forming tool toform indicia on a sheet metal material formed therebetween.
 54. A pairof forming tools according to claim 53, wherein the first formingsurfaces of the forming tools are configured to cooperate, in use, tocold work a sheet metal material therebetween and the second formingsurfaces of the forming tools are configured to cooperate to emboss thesheet metal material therebetween.
 55. A pair of forming tools forforming sheet metal material therebetween, each of the forming toolscomprising a respective first forming surface and a respective secondforming surface, wherein the first forming surfaces cooperate, in use,to form a pattern of projections in or on a sheet metal material formedtherebetween on both major surfaces of said sheet material by coldworking while the second forming surfaces cooperate to form indicia byembossing at an interruption in the pattern of projections in or on asheet metal material formed therebetween, the second forming surfacesbeing configured such that the indicia is distorted if the tools aremisaligned.
 56. A pair of tools according to claim 55, wherein thesecond surfaces comprise cooperating forming edges separated by apredetermined distance, in use, when a sheet metal material is formedbetween the tools when the tools are in proper alignment.
 57. A pair oftools according to claim 55, wherein the first forming surfacescooperate, in use, to form an array of projections and depressionsdistributed such that lines drawn on a surface of the formed sheetmaterial between adjacent rows of projections and depressions are notrectilinear.
 58. A pair of tools according to claim 55, wherein thesecond forming surface of each tool is surrounded or bound by the firstforming surface thereof.
 59. An apparatus for forming sheet metalmaterial, the apparatus comprising a pair of opposed tools according toclaim 55, movably mounted relative to one another, wherein the firstforming surfaces comprise projections or teeth, the geometry andposition of the projections or teeth and the spacing of the tools beingsuch that the projections or teeth on one tool register and/or extend,in use, into gaps between the projections or teeth on the other tool.60. A formed sheet metal material comprising a pattern of projectionsformed on or in a first portion or region thereof and indicia formed onor in a second portion or region thereof at an interruption in thepattern of projections, wherein the pattern comprises projections onboth major surfaces of the sheet material and is formed by cold working,wherein the indicia are formed by embossing and are usable to provide anindication of the alignment of tools used to cold work the sheetmaterial.
 61. A formed sheet material according to claim 60, wherein thepattern is configured and/or distributed such that lines drawn on asurface of the formed sheet material between adjacent rows ofprojections and depressions are not rectilinear.
 62. A formed sheetmetal material according to claim 60, wherein at least a portion of theindicia provides a visual and/or machine readable indication of thealignment of tools used to form the sheet material.
 63. A formed sheetmetal material according to claim 60, wherein the second portion isbound by the first portion.
 64. A profile or beam or article having ashaped cross-section, the profile or beam or article having a shapedcross-section comprising a sheet metal material according to claim 60.